The present invention relates to an ink supply arrangement for a printer.
More particularly, though not exclusively, the invention relates to an ink supply arrangement for an A4 pagewidth drop on demand printhead capable of printing up to 1600 dpi photographic quality at up to 160 pages per minute.
The overall design of a printer in which the arrangement can be utilized revolves around the use of replaceable printhead modules in an array approximately 8 inches (20 cm) long. An advantage of such a system is the ability to easily remove and replace any defective modules in a printhead array. This would eliminate having to scrap an entire printhead if only one chip is defective.
A printhead module in such a printer can be comprised of a xe2x80x9cMemjetxe2x80x9d chip, being a chip having mounted thereon a vast number of thermo-actuators in micro-mechanics and micro-electromechanical systems (MEMS). Such actuators might be those as disclosed in U.S. Pat. No. 6,044,646 to the present applicant, however, there might be other MEMS print chips.
The printhead, being the environment within which the ink supply arrangement of the present invention is to be situated, might typically have six ink chambers and be capable of printing four color process (CMYK) as well as infra-red ink and fixative.
Each printhead module receives ink via a distribution molding that transfers the ink. Typically, ten modules butt together to form a complete eight inch printhead assembly suitable for printing A4 paper without the need for scanning movement of the printhead across the paper width.
The printheads themselves are modular, so complete eight inch printhead arrays can be configured to form printheads of arbitrary width.
Additionally, a second printhead assembly can be mounted on the opposite side of a paper feed path to enable double-sided high speed printing.
An elongate pagewidth printhead assembly might be efficiently packaged into a printer housing if its ink supply hoses did not project longitudinally beyond the pagewidth extent of the assembly.
It is an object of the present invention to provide an ink supply arrangement for a printer.
It is another object of the present invention to provide a printhead assembly receiving ink from a hose that does not extend beyond the longitudinal or pagewidth extent of the assembly.
It is another object of the present invention to provide an ink supply arrangement suitable for the pagewidth printhead assembly as broadly described herein.
It is another object of the present invention to provide an ink supply arrangement for a printhead assembly on which there is mounted a plurality of print chips, each comprising a plurality of MEMS printing devices.
It is yet another object of the present invention to provide a method of distributing ink to print modules in a printhead assembly of a printer.
The present invention provides a printhead assembly comprising:
an elongate pagewidth ink distribution housing having a longitudinal extent in a pagewidth direction and conveying ink to a plurality of ink ejection nozzles substantially spanning said pagewidth, the housing including an inlet port configured to receive an ink hose via which ink is received by the housing, wherein the hose extends from the port in a direction that is substantially normal to said pagewidth direction.
Preferably the inlet port is positioned substantially midway between respective opposed ends of the housing.
Preferably the printhead assembly includes a pagewidth array of print modules each having said ink ejection nozzles thereon.
Preferably the printhead assembly is configured to print color images and wherein there is provided a number of said inlet ports corresponding to the number of colors to be printed.
Preferably there is provided a number of ink hoses corresponding to the number of ports and all of the ink hoses extend from the ports in a direction that is substantially normal to said pagewidth direction.
Preferably the printhead assembly is mounted within a printer and including a stepper motor for driving ancillary equipment of the printer, the stepper motor being located not beyond the longitudinal extent of the ink distribution housing.